2,2,2-trichloro-4&#39;-tert butyl-acetophenone

ABSTRACT

1. 2,2,2-TRICHLORO-4&#39;&#39;-TERT.BUTYLACETOPHENONE.

United States Patent 3,850,989 2,2,2 TRICHLORO 4' TERT BUTYL-ACETOPHENONE Reginoldus Havinga, Schalkhaar, and Pieter Dirk Swaters,Lochem, Netherlands, assignors to Akzo N.V., Arnhem, Netherlands NoDrawing. Filed Apr. 3, 1973, Ser. No. 347,563 Claims priority,application Netherlands, Apr. 21, 1972, 7205384 Int. Cl. G07c 49/80 US.Cl. 260--592 1 Claim ABSTRACT OF THE DISCLOSURE A process for curingacid-curable resins with photocatalyst compounds having the generalformula:

0 )m ll wherein m=0, 1 or 2 and p is an integer from 1 to and wherein,when p is 1, R represents an alkyl or alkoxy group having at least 4C-atoms, and when p 1, R represents alkyl or alkoxy groups havingtogether at least 4 C-atorns. The photocatalyst which may be used is2,2,2- trichloro-4'-tert butylacetaeetophenone. This compound may beprepared by chlorinating 4'-tert-butylacetophenone or by treatingtert-butyl benzene in carbon disulfide with trichloroacetyl chloride ortrichloroacetonitrile and aluminum chloride.

The present invention relates to acid-curable resins and is concerned inparticular with a process for curing such resins using a photocatalyst,with a new photocatalyst and its process of preparation to be used inthe curing process according to the present invention and with theresultant resins obtained by the curing process of the presentinvention.

It is known that resins, such as phenol resins and amino resins,particularly urea resins and melamine resins, may be cured separately orin combination with other resins, such as alkyd resins, by irradiationwith ultra-violet light. For this purpose, compounds which cause curingof the resin or resin mixtures by generating acids under irradiationhave to be incorporated in the resin or resin mix- DS-m in which mi=0, 1or 2 and p is an integer from 1 to 5 and wherein when p is 1, Rrepresents an alkyl or alkoxy group having at least 4 C-atoms, and whenp is 1, R

3,850,989 Patented Nov. 26, 1974 ice represents alkyl or alkoxy groupshaving together at least 4 C-atoms, are excellently suited for beingused as photocatalysts for acid-curing resins, because they possess ahigh effectivity.

Moreover, the trichloro-compounds to be used according to the presentinvention have the advantage that they dissolve more easily in lacquersat room temperature as compared with the correspondingtribrorno-compounds. Moreover, lacquers containing compounds accordingto the present invention have a better stability on storage in the darkthan lacquers containing the corresponding bromine-containing compounds,as illustrated in the following Table. The viscosity referred to in thistable was determined by measuring the time needed for a steel ball,weighing 33 mg. and having a diameter of 2.0 mm., to fall 130 mm.through a vertical column of the lacquer having a diameter of 14 mm. andthen converting this time into poises. The lacquer used is described inExample I below. The compounds used are2,2,2-trichloro-4'-tert-butylacetop henone (A) and the correspondingtribromo derivative (B).

Viscosity at 40 after Viscosity at after stated stated number Quantitynumber of days of days 1! weight 0 1 5 9 12 19 0 30 1% 0.4 0.6 1.1 3 2i6 g 1.1 1. 8 2% 0.6 0.7 1.0 1 9 16 g 1.1 1.7 1% 0.6 0. 8 16 g 1. 1 3. 32% 0.8 1. 0 g 1. 2 3. 8

Illustrative examples of compounds according to the general formulahereinbefore defined. are: 2-chloro-4'-tert. butylacetophenone; 2,2di-chloro-4'-tert.butylacetophenone; 2-chloro-4' octylacetophenone; 2,2di-chloro-4'- octylacetophenone; 2 chloro 4'-n-C -alkylacetophenone;2,2-dichloro 4'-n-C -alkylacetophenone; 2,2,2- trichloro-4'-n-Calkylacetophenone in which the alkyl groups range from 8-13 carbon atoms(derived from C alkylbenzene with the trade name Dobane 83 X);2,2-dichloro-4-octyloxyacetophenone; 2,2,2 trichloro-4'-octyloxyacetophenone; 2,2-dichloro-2',4' diisopropylacetophenone;2,2,2-trichloro-2',4' diisopropylacetophenone or mixtures of thesecompounds. Preferably, however, the new compound 2,2,2-trichloro4-.tert.buty1acetophenone is used. This compound may be prepared in ananalogous way to that described in J.A.C.S. 72 (1950) pages 39523 forthe preparation of trichloroacetophenone, namely by treating4-tert.butylacetophenone with chlorine. The starting4-tert.buty1acetophenone may be obtained in the manner described inJ.A.C.S. 68 (1946) page 1107 by a Friedel-Crafts acetylation of tertbutylbenzene with acetyl chloride in a solvent, such as carbontetrachloride. The compound 2,2,2 trichloro-4'-tert.butylacetophenonemay also be obtained in an analogous way to that described inHouben-Weyl 5/3, page 790 for the preparation of trichloro-2',4',6'trimethylacetophenone. The compound may also be prepared directly by aFriedel-Crafts reaction of tert.butylbenzene with trichloroacetylchloride in carbon disulphide as described in J. Indian Chem. Soc. 26(1947), pages 287-9. It is also possible to use trichloroacetonitrileinstead of trichloro-acetyl chloride as described in J. Prakt. Chem. (2)123 (1929), 313.

Suitable resins which may be cured by making use of the photocatalystsaccording to the invention are, for ex- 3 ample, urea and melamineresins separately or in combination with other resins, such as alkydresins. The photocatalysts to be used according to the present inventionmay be incorporated in white or lightly pigmented lacquers to be put onany substrate, such as wood, metal or textile materials or those usedfor reproduction purposes.

The compounds to be used according to the present invention are usuallyadded to the resins in quantities of 0.5-l% by weight, preferably 15% byweight calculated on the resin to be cured. They may be incorpo rated inthe resin to be cured as such or dissolved in suitable solvents, such asisopropanol, xylene n-butanol or mixtures thereof, or mixed with aninert resin, such as an alkyd, resin by means of the usual techniques.

The acid-curing resins to be cured according to the present inventionmay be employed as lacquers or printing-inks. To this end, compositionsconsisting of the acid-curing resins and the selected photocatalysts arepreferably dissolved in suitable solvents, such as isopro panol, Xyleneor n-butanol, are then applied to a substrate, such as wood, paper or atextile, and then cured with the aid of U.V. irradiation. In addition tothe abovementioned solvents, pigments, plasticizers and fillers may beincorporated in the compositions, if desired. The following examplesillustrate without limitation the present invention. Parts andpercentages are by weight unless otherwise stated.

EXAMPLE I The photocatalysts mentioned hereinafter in Table 2 were addedto a lacquer to be cured by acid, consisting of parts of a 70% solutionof an alkyd resin in an isopropanol-Xylene mixture (ratio 9:1), mixedwith 47.5 parts of a solution of a urea resin in butanol and 2.5 partsof a solution of a melamine resin in butanol. The alkyd resin had beenprepared from a mixture consisting of 34% phthalic anhydride, 2.polyalcohol and a vegetable oil having a short oil length in an amountof 38%. The percentages indicated are based on the total amount oflacquer.

The mixtures obtained were spread on glass plates to a film-layerthickness of These layers were irradiated with a Philips high pressuremercury lamp, type HTQ-4, at a distance of 20 cm. for 60 and seconds.The results are tabulated in Table 2. The so-called Persoz-hardness wasused as a measure for the curing, as described in French norm NF T30016. The stability of the mixtures on storage in the dark at roomtemperature was determined by measuring the viscosity according to themethod already described. After 4 weeks, no change in viscosity of anyof the mixtures could be observed.

TABLE 2 Drying time in Persoz-hardness in min. Irradiaminutes to after1, 7, or 21 days Quantion tity in time Taek- Hard Photocatalyst percentin sec. tree dry 1 7 21 W ou photocatalyst S8 233 g22-ch1oro-4-tert.butylacetophenone 1.0 38 3 2 0 60 5 18 213 292 324 120 13 205 295 310 2,24lichloro-4-tert.butylacetophenone- 0. 25 1%?) 88 i 1202 28 286 are 1 0 e0 5 21 244 295 304 120 1 4 236 288 305 2 0 60 3 15 236288 315 120 1 2 241 292 308 4 0 60 2 6 215 273 295 120 0 1 225 280 2942,2,2-trichloro-4-tert.butylacetophenone 0.25 120 5 32 173 260 268 0 5060 5 16 223 286 304 120 2 4 204 288 310 1 0 60 2 8 256 295 30s 120 0 2242 298 325 2 0 60 1 5 256 279 302 120 0 1 238 280 308 4 0 so 1 2 230254 271 120 0 0 228 258 292 zchloro-4-octylacetophenone 1 0 28 g 2 0 605 15 233 294 316 120 0 2 238 308 320 2,2-dlchloro-4-octylacctophenone1.0 38 g g 2 0 60 2 8 143 196 316 120 0 1 245 316 3282-ehloro-4-n-a1kylacetophenone 1 1. 0 38 3 32 38g 2 0 60 2 38 231 308320 120 1 4 256 302 334 2,2-dichloro-4m-alkylacetophenone 1. 0 33 31 2 060 2 13 252 305 330 120 0 3 260 304 3222,2,2-triehl0ro-4-n-a1kylacetophenone 2. 0 120 0 2 235 308 3272,Z-dichloro-4-octyloxyacetophenone 2. 0 120 0 2 231 312 3282,2,2-trichloro4'-oetyloxyacetophenone 2. 0 120 0 2 230 302 3222,2-dichloro-2'-4-diisopropylacetophenone 2. 0 120 0 2 216 300 3062,2,2-trichlor0-2,4-diisopropylacetophenone 2. 0 120 0 2 221 305 311 1By which the alkyl group varies from 8 to 13 carbon atoms (derived from05-13 alkylbenzene with the trade name Dobane 83 X).

EXAMPLE n 1.0 and 2.0 parts respectively of photo catalysts were addedto a lacquer to be cured by acid consisting of 41.6 parts of a 60%solution of an alkyd resin in xylene, mixed with 41.6 parts of a 60%solution of a non-plasticizcd, butylized urea formaldehyde resin inbutanol and made up to 100 parts with 9.6 parts of isopropanol and 7.2parts of butanol. The alkyd resin was prepared from a mixture consistingof of phthalic acid anhydride, a polyalcohol and 42% of oil rich inlinolic acid. The results obtained after curing are tabulated in Table3.

EXAMPLE III 1.0 and 2.0 parts respectively of the photocatalystsmentioned in Table 4 were added to a lacquer to be cured by acidconsisting of 83.2 parts of a solution of an internally plasticized urearesin in a butanol-xylene mixture (ratio 2:8), made up to parts with 9.6parts of isopropyalcohol, 1.1 parts of butanol and 6.1 parts of xylene.The results obtained after curing are tabulated in Table 4.

TABLE 4 Persoz-hardness Quan- Drying in minutes tity Irradiatime inafter 1, 7, or in tion minutes 21 days pertime to hard Photoeatalystcent in sec. dry 1 7 21 V 60 500 50 63 82 Without photoeatalyst 500 6174 96 2,2-dicl1loro-1-tert. butyl- 6O 18 112 240 236 acetophenone 1. 0120 10 134 208 247 4 O 60 20 148 226 253 120 3 152 239 2592,2,2-trichloro-4-tert. 6O 10 127 213 250 buty1acetophenone 1.0 120 6209 253 2 0 60 8 164 240 261 120 0 176 245 274 EXAMPLE IV ride was addedover a period of 1 hour at a temperature below 10 C. Subsequently, 469grams (3.5 mol) of ten.- butylbenzene was added to the reaction mixtureover a 6 period of 3 hours at a temperature below 5 C. After stirringfor 1 hour without cooling, the reaction mixture was poured into amixture of 500 milliliters of water, 1.7 kilograms of ice andmilliliters of 35% hydrochloric acid. The organic phase was separated,washed to neutrality and dried. After the solvent had been distilledoff, 600 grams of 4-tertbutylacetophenone was obtained having arefractive index n =1.5212. 444 grams (2.02 mol) of the above-described4--tert.butylacetophenone was mixed with 1.25 liters of glacial aceticacid and heated to 60 C. while stirring. Subsequently, at a reactiontemperature of about 60 C., 375 grams (5.28 mol) of gaseous chlorine waspassed into the reaction mixture for 4% hours. After the reactionmixture had been freed from hydrogen chloride gas and the excess ofchlorine by passing through nitrogen, 414 grams (5.05 mol) of anhydroussodium acetate was added and then the reaction mixture was heated to 95C. Subsequently, another grams (2.60 mol) of gaseous chlorine was passedinto the reaction mixture for 2 hours at a temperature of about 95 C.The excess chlorine was again removed with the aid of nitrogen and thenthe hot reaction mixture was filtered. After the addition of 63milliliters of Water, the clear filtrate was cooled to room temperature,which caused 2,2,2-trichloro-4'-tert.butylacetophenone to crystallizeout. After filtering otf by suction, washing and drying, 530 grams ofwhite crystalline final product was obtained, having a melting point of61.562.5 C

EXAMPLE V References Cited FOREIGN PATENTS 5/ 1970 East Germany 260-592OTHER REFERENCES Houben-Weyle 5/3, p. 790 (1962). Cohen et al., J. Am.Chem. Soc. 72, 39524953 (1950).

DANIEL D. HORWITZ, Primary Examiner

1. 2,2,2-TRICHLORO-4''-TERT.BUTYLACETOPHENONE. 